This research argues that using an electron beam with high kinetic energy to pump perovskite quantum dots can significantly boost the efficiency of the low-frequency photon radiation conversion.Firstly,we measure the ...This research argues that using an electron beam with high kinetic energy to pump perovskite quantum dots can significantly boost the efficiency of the low-frequency photon radiation conversion.Firstly,we measure the random lasing threshold and luminescence threshold of CsPbX_(3)films pumped by an electron beam.Then,we simulate the spatial distribution of the electron beams in CsPbX_(3)films.Combined with the above data,a low-frequency photon radiation conversion model based on the electron pumped perovskite quantum dots is presented.This could be a way to create a terahertz source with a high-power output or to multiply the terahertz power.展开更多
Octa（aminophenyl）silsesquioxane （OAPS） was used as the curing agent of diglycidyl ether of bisphenol-A （DGEBA） epoxy resin. A study on comparison of DGEBA/OAPS with DGEBA/4,4＇-diaminodiphenyl sulfone （DDS） ep...Octa（aminophenyl）silsesquioxane （OAPS） was used as the curing agent of diglycidyl ether of bisphenol-A （DGEBA） epoxy resin. A study on comparison of DGEBA/OAPS with DGEBA/4,4＇-diaminodiphenyl sulfone （DDS） epoxy resins was achieved. Differential scanning calorimetry was used to investigate the curing reaction and its kinetics, and the glass transition of DGEBA/OAPS. Thermogravimetric analysis was used to investigate thermal decomposition of the two kinds of epoxy resins. The reactions between amino groups and epoxy groups were investigated using Fourier transform infrared spectroscopy. Scanning electron microscopy was used to observe morphology of the two epoxy resins. The results indicated that OAPS had very good compatibility with DGEBA in molecular level, and could form a transparent DGEBA/OAPS resin. The curing reaction of the DGEBA/OAPS prepolymer could occur under low temperatures compared with DGEBA/DDS. The DGEBA/OAPS resin didn＇t exhibit glass transition, but the DGEBA/DDS did, which meant that the large cage structure of OAPS limited the motion of chains between the cross-linking points. Measurements of the contact angle indicated that the DGEBA/OAPS showed larger angles with water than the DGEBA/DDS resin. Thermogravimetric analysis indicated that the incorporation of OAPS into epoxy system resulted in low mass loss rate and high char yield, but its initial decomposition temperature seemed to be lowered.展开更多
基金funded by the National Natural Science Foundation of China(Grant Nos.61905026,61703057,11874091,and 61905023)the National Key Research and Development Program of China(Grant No.2018YFB1800303)+2 种基金Construction Project of Key Laboratory of Astronomical Optics Technology of Chinese Academy of Sciences(Grant No.CAS-KLAOTKF201803)Chongqing Natural Science Foundation of China(Grant No.CSTC2021JCYJMSXMX0500)Foundation Project of Jilin Province,China(Grant Nos.20210402067GH,JJKH20210830KJ,JJKH20210800KJ,20200301065RQ,20190201188JC,and2019C043-6)。
文摘This research argues that using an electron beam with high kinetic energy to pump perovskite quantum dots can significantly boost the efficiency of the low-frequency photon radiation conversion.Firstly,we measure the random lasing threshold and luminescence threshold of CsPbX_(3)films pumped by an electron beam.Then,we simulate the spatial distribution of the electron beams in CsPbX_(3)films.Combined with the above data,a low-frequency photon radiation conversion model based on the electron pumped perovskite quantum dots is presented.This could be a way to create a terahertz source with a high-power output or to multiply the terahertz power.
文摘Octa（aminophenyl）silsesquioxane （OAPS） was used as the curing agent of diglycidyl ether of bisphenol-A （DGEBA） epoxy resin. A study on comparison of DGEBA/OAPS with DGEBA/4,4＇-diaminodiphenyl sulfone （DDS） epoxy resins was achieved. Differential scanning calorimetry was used to investigate the curing reaction and its kinetics, and the glass transition of DGEBA/OAPS. Thermogravimetric analysis was used to investigate thermal decomposition of the two kinds of epoxy resins. The reactions between amino groups and epoxy groups were investigated using Fourier transform infrared spectroscopy. Scanning electron microscopy was used to observe morphology of the two epoxy resins. The results indicated that OAPS had very good compatibility with DGEBA in molecular level, and could form a transparent DGEBA/OAPS resin. The curing reaction of the DGEBA/OAPS prepolymer could occur under low temperatures compared with DGEBA/DDS. The DGEBA/OAPS resin didn＇t exhibit glass transition, but the DGEBA/DDS did, which meant that the large cage structure of OAPS limited the motion of chains between the cross-linking points. Measurements of the contact angle indicated that the DGEBA/OAPS showed larger angles with water than the DGEBA/DDS resin. Thermogravimetric analysis indicated that the incorporation of OAPS into epoxy system resulted in low mass loss rate and high char yield, but its initial decomposition temperature seemed to be lowered.
